Motor horn



Patented Mar. 13, 1928.

UNITED STATES PATENTA OFFICE.

LOUIS CHOLLET, OF PARIS, FRANCE, ASSIGNOR `'IO COMPAGNIE INDUSTRIELLE ET COMMERCIALEDU CYCLE ET DE L.AUTOMOBILE OF PARIS, FRANCE.

Moron HORN.

Application filed February 7, 1925, SerialvNo. 7,566, andin France` February 8, 1924.

to give it a camber at its edges sloping t-r wards the mouth of the horn or the edges of the membrane itseli"l are cambered or these two cambers are combined.

The apparatus as applied to a bulb horn 1s illustrated in the accompanying drawings in which Figure 1 is a sectional elevation and Figure 2 a plan view on the line m-aa Fig. 3, is an enlarged sectional detail showing the sound-dome, membraneand support-y ing ledge.

As illustrated, the horn is sounded by a rubber bulb P or the like which may be operated by hand pres-sure by means o f a lever, or by the toot, as in many existing systems.

lhe bulb ,P is mounted on a tube 1 con`` neeted to the cover 2 of a casing 3, and cover Q is internallyscrcw threaded at 4: andy screws on to casing 3. Thecover 2 has on it a shoulder 5 'for securing the parts within casing 3.

The casing 3 is prolonged to form a tube 6 which is externally screw threaded for mounting the horn on a suitable part of the apparatus, on which it is to be used, by plates and screws,yas in practice.

WVithin the tube 6 is a long tube 7 forming an extension of the horn piece 8, and 9 is a screw for locking tube 7 in tube 6 in any desired position. The bevelled end portion 10 ot tube 7 forms the mouth' of the horn piece and by adjusting the position of the tube 7 in the tube 6, the position of 10 relatively to a membrane can'be varied. n

Casing -has on it. an internal rim 11 which supports tongues 12 carried by a ring 13. This ring itselt has a beveled edge 14 on which is placed the edge of a vibrating membrane 15.

The air owsptreely between the ring 13 and the body of the casing 3, in order to act under the vibrating `membrane 15. y

17 is a sound dome having on it three or 'four projections 16 which rest on the ring country.

13; dome 17 is bevelled at 18 inversely and to a greater degree than the bevel le onring 13. Villen membrane is in position and also dome 17, the cover 2 will, through its shoulder 5, exert pressure on projection 16, and therefore cause the cambering of the edges of membrane 15 between bevels 14 and 18, so stretching it and giving to it the necessary rigidity and elasticity.

When assembling the parts, tube 7 is screwed in the tube G till the position of maximum sound is 'found and isjthen secured by a'nut 9. ready tor use. ,It will be found that this position is one in which mouth 10 does not, when the horn is sounded, come into contact with membrane 15 because the bulb, after it f has sounded, immediately refills, as there is a tree passage Vot air past' membrane 15, thus no pressure ortension is exerted on the membrane. y

It in reed instruments the bulbis pressed hard the excessive pressure of the air emitted therefrom causes the diaphragm to block the mouth oit the horn. In this case, however, sound would bel immediately emitted with great torce as air from tube 1 passed through the space formed between the periphery ot the ring 13 and the wall of casing 3, and so beneath membrane 15 where it would act with all its force; above the membrane the air expands slightlyv in dome 17 so that `membrane 15 is raised in spite of the dilierences in the surfaces.

vThere is thus no possibility ot blocking mouth 10 so rendering it superior to reed instruments, and moreover the strength of the sound given canvary from a sound suit able for town to a sound loud enough for the It should be understood that if airis caused to pass into the casing from some continuousy source of airfsuch as a pump, the

apparatus will4 give a continuous sound, as in other known instruments, but it only necessitates a small source of energy, since neither the blocking of the mouth-piece nor the tension of the membrane or spring has to be overcome. f

4 The two feeds may be combined in which case the cover 2 has in addition a fitting for the airsource as well as the tube 1, a nonreturn valve or the like being also provided so that when the bulb is used, theair from The apparatus is thenY rim this will not expand in the channels of the air source but will pass through the membrane.

The membrane is preterablj;7 rectangular in :shape and eoverS the mouth l0. Due to its particuhir thickness, the membrane provides a small space between the edges of the dome 1T and those of ring 13. This space allows the air to act above the membrane, in the same way as below the latter. It it was completely circular, the apparatus would be lsimilar to those membrane apparatus already known: it would then be necessary to eamber the membrane on to the mounth. and therefor-e to use a much greater air pressure.

The. thickness and dimeneions and so the weight of the memlnane depend upon the tone of the instrument` i. e. the horn piece.

The tensitm produced by the bevels 14.18 may be increased h v Slightly eambering the edges of the memlnane itself; moreover, the bevels ll- 18 may berutirely done away with, but itt so, the membrane must have its cambered. This membrane may be made of anyv material that: can be so tensioned or cambered.

The caeingl ma)v have a minimum diameter of 5 to (3 em., and the membrane may be formed ol a plate olt l to il em., b v .l cm.

Havingr now partiettlarly described and ascertained the nature ot our inve-ntitm and in what nunmer the same is to be performed, we decla re that what we claim isza l. In a horn, a tubular easing with an open upper end, a horn piece extension tube entendiim up into the casing, a memlirane carrying ring mounted in the open end of the casing so that its rim is in spaced relation to the wall oli the casing, a membraneous strip extending across the ring in proX imity with the upper end olf' the extension tube and its width beine" less than the internal diameter oi? the ring'` a sound dome mounted on the ring'. and a cover.' extending over the open end ol the easing, compressed air supplying meane and means for directingI the air trom the. manpreseed air Supplyine means onto both taees of the n'lenibraneousl strip wherebyv such Ietrip is vibrated.

2. A horn comprising a horn piece.v an extension tube therefor. a. tubular casinor into which the exteneion tube extends, Said caeing beiner open at its top end, a cover 'for the open end ot the casing, compressed air :supplyingr means eonnnunieatinfl with the interior of the casing. a membrane Supported in the open end ot the easing in proximity to the open end of the exteneion tube and so Constructed ne to permit the air to pass upwardlj,Y between such membrane and the wall 0f the casing', an imperforate sound dome supported above the membrane for preventing the downwardly moving air from impine'inlgl directly onto the upper surface of the membrane, said membrane being supported in such a manner that air spaces are con- Stituted between its outer periplurry and the. wall ol the easing, the air 'from the cornpressed air Supplying meansI beine, deflected outwardly by tbe sound dome to 'arde the air Spaces between the sound dome and the wall ol the easing, down through auch air spaces, upwardly agraire-it the underneath face ol the. mernlufauc and through the spaces between the membrane and (faxing wall against the sound dome wherebjtv it is deflected onto the upper face ot' the membrane for vibrating it.

3. In a horn, a tubular casing: with an open upper end7 a horn piece extension tube extendiimr up into the casing, a membrane earrying' ringil mounted in the open end of the casingV so that its rim is in spaced rclation to the wall of the cugina, a memln'ane ons strip extendingr aero1 the riner in proximity with the upper end of the extension tube and its width beine; lees than the iuternal diameter ol the ring, a sound dome mounted on the ring, a cover extendin; rJ over the open end of the easing, and means on the interior ot the cover engaging the sound dome for securingy it, the membrane support ing ring and the membraneouay strip in position, conipressed air supplyingr means and means' 'tor directing,m the air from the compressed air supplying; means onto both tat-ea of the n1e1nbrzmeouf-i` et rip wherebyv auch Strip is vibrated.

4. In a horn, a tubular easing haring;r an open end, a memln'aneoua strip supporting ring mounted in the open end oll the easing, a memln'aneous strip mounted on the ring, said rimer having a bevel upon which the ends ot the meml'naneoue strip reet, a Sound dome harinar a bevel greater in degree than the bevel on the ring,` and meanel enacting with the sound dome tor pressing the bevel thereon downwardl;7 into engagement with the ends of the membranetnle strip.

lfn a horn. a tubular easing having:r an open end, a membrane supper-timer ring mounted in the open end of the casing, a membrane mounted on the ring, and means gripping;- the ende of the membrane for stretchingA it, to the required tension.

(i. ln a horn, a tubular easing' having an open end` a membrane stuiporting ring mounted in the open end et the casing, a member superimposed above the ring,r and coaetiner means on the ringr and member gripping the membrane between them for stretching it to the required tension. 

